Ptcr - Manitowoc S300 Technician's Handbook

PTCR

The PTCR allows current to flow through the start
winding at compressor startup. Current flow heats the
ceramic discs in the PTCR. The electrical resistance
increases with temperature and stops all except a
trickle of current flow through the start winding. The
small flow of current keeps the PTCR hot (260°F/
127°C) and the start winding out of the circuit.
The PTCR must be cooled before attempting to start
the compressor, otherwise the PTCR will heat up too
quickly and stop current flow through the start winding
before the compressor motor reaches full speed..
Disconnect e lectrical p ower to the en
machine at the bu ilding el ectrical disco nnect box
before proceeding.
NOTE: If a PTCR is dropped internal damage can
occur to the ceramic PTCR discs. The ceramic disc
can chip and cause arcing which leads to PTCR
failure. Since there is no way to open the PTCR in
order to determine if the ceramic disc is chipped or
not, it must be discarded when dropped.
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Warning
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Part Number 80-1479-3 7/10
tire ice